Replication of murine hepatitis virus is regulated by papain-like proteinase 1 processing of nonstructural proteins 1, 2, and 3.

ABSTRACT: Coronaviruses are positive-strand RNA viruses that translate their genome RNA into polyproteins that are co- and posttranslationally processed into intermediate and mature replicase nonstructural proteins (nsps). In murine hepatitis virus (MHV), nsps 1, 2, and 3 are processed by two papain-like proteinase activities within nsp3 (PLP1 and PLP2) to yield nsp1, an nsp2-3 intermediate, and mature nsp2 and nsp3. To determine the role in replication of processing between nsp2 and nsp3 at cleavage site 2 (CS2) and PLP1 proteinase activity, mutations were engineered into the MHV genome at CS2, at CS1 and CS2, and at the PLP1 catalytic site, alone and in combination. Mutant viruses with abolished cleavage at CS2 were delayed in growth and RNA synthesis but grew to wild-type titers of >10(7) PFU/ml.

SUBMITTER: Graham RL 

PROVIDER: S-EPMC1642617 | biostudies-literature | 2006 Dec

REPOSITORIES: biostudies-literature